U.S. patent application number 10/750761 was filed with the patent office on 2004-07-15 for method and system for displaying an image on a screen.
This patent application is currently assigned to VARYFRAME TECHNOLOGIES LTD. Invention is credited to Kamir, Yosef, Steinblatt, Serge, Weiss, Alex.
Application Number | 20040135868 10/750761 |
Document ID | / |
Family ID | 25124316 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040135868 |
Kind Code |
A1 |
Kamir, Yosef ; et
al. |
July 15, 2004 |
Method and system for displaying an image on a screen
Abstract
A public presentation system is presented comprising a display
system that can be remotely changed, so that multiple different
images are successively displayed with minimal interruption. The
system utilizes ionography techniques for non-contact printing and
imaging for display. Thus by exploiting electrostatic imaging
techniques, an advertisement can be displayed promptly by
transferring a toner image onto an imaging belt.
Inventors: |
Kamir, Yosef; (Mathanya,
IL) ; Weiss, Alex; (Kadima, IL) ; Steinblatt,
Serge; (Raanana, IL) |
Correspondence
Address: |
DR. MARK FRIEDMAN LTD.
C/o Bill Polkinghorn
Discovery Dispatch
9003 Florin Way
Upper Malboro
MD
20772
US
|
Assignee: |
VARYFRAME TECHNOLOGIES LTD
|
Family ID: |
25124316 |
Appl. No.: |
10/750761 |
Filed: |
January 5, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10750761 |
Jan 5, 2004 |
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09781900 |
Feb 13, 2001 |
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6686941 |
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Current U.S.
Class: |
347/115 |
Current CPC
Class: |
G09F 11/26 20130101 |
Class at
Publication: |
347/115 |
International
Class: |
B41J 002/385 |
Claims
What is claimed is:
1. A display system comprising: at least one display screen;
printing means for transferring color images on to said at least
one display screen; erasing means for erasing said color images
from said at least one display screen; and drive means connected to
said at least one display screen for operatingly moving said at
least one display screen.
2. The system according to claim 1 and wherein said drive means
moves said at least one display screen from a first printing
position to a second viewing position.
3. The system according to claim 1 and further comprising: an
interface control unit coupled to at least said at least one
display screen; and processing means communicating with said
interface control unit to control the display of said images.
4. The system according to claim 1 wherein each of said at least
one display screen comprises a plurality of display screens, each
of which displays a separate color separation of said image.
5. The system according to claim 1 and further comprising a dual
purpose screen having a substantially white reflective diffusing
portion and a substantially transparent portion.
6. The system according to claim 1 and further comprising a
substantially transparent protective screen placed in front of said
at least one display screen.
7. The system according to claim 4 wherein each of said plurality
of display screens comprises an endless dielectric imaging
belt.
8. The system according to claim 4 wherein each of said separate
color separation images is a digitized version for one of each of
the four color separations of cyan, magenta, yellow and black (C,
M, Y and K).
9. The system according to claim 4 wherein said printing means
comprises: a separate toner reservoir for each of said separate
color separation images; and writing means for applying toner from
each of said separate toner reservoir onto each of said at least
one display screen.
10. The system according to claim 1 wherein said erasing means
comprises: static eliminators for cleaning and erasing the toner
from said at least one display screen; and at least one receptacle
for said at least one display screen for receiving and storing the
removed toner.
11. The system according to claim 10 wherein said static
eliminators comprise one of a group of eliminators including active
hot static eliminators; active shockless static eliminators and
passive static eliminators.
12. The system according to claim 10 and further comprising pumping
means to transfer toner from each of said at least one receptacle
to the corresponding toner reservoir.
13. The system according to claim 5 wherein said drive means is
connected to said dual purpose screen for operatingly moving said
dual purpose screen from a first position wherein said
substantially white reflective diffusing portion is placed behind
said at least one display screen to a second position wherein said
substantially transparent portion is placed behind said at least
one display screen.
14. The system according to claim 3 wherein said interface control
unit is coupled to said drive means.
15. A method for producing at least one display image onto a
screen, said method comprising the steps of: preparing said at
least one display image; communicating said at least one display
image to an interface and control unit; printing said prepared at
least one display image on to at least one display screen; and
moving said at least one display screen into position for
viewing.
16. A method according to claim 15 and further comprising the step
of erasing said displayed image.
17. A method according to claim 15 and further comprising the steps
of: preparing a replacement display image; and communicating said
replacement display image to said interface and control unit.
18. A method according to claim 17 and further comprising the step
of concurrently printing said replacement display image while a
previous, displayed image is being erased.
19. A method according to claim 17 and further comprising the step
of printing said replacement display image on a separate part of
said at least one display screen while said first image is being
displayed.
20. A method according to claim 17 and further comprising the step
of erasing a first image and concurrently printing a replacement
display image on a separate part of said at least one display
screen while another image is being displayed.
21. A method according to claim 17 and further comprising the step
of replacing said first image with said replacement display
image.
22. A method according to claim 15 and further comprising the step
of moving a dual purpose screen having a substantially white
reflective diffusing portion and a substantially transparent
portion behind said at least one display screen.
23. A method according to claim 22 wherein said moving step
comprises the step of activating said dual purpose screen to move
said substantially transparent portion behind said at least one
display screen whenever the amount of light falls below a
predetermined level.
24. A method according to claim 15 wherein each of said at least
one display screen comprises a plurality of display screens each of
which displays a separate color separation of said image.
25. A method according to claim 24 wherein said printing step
comprises the steps of: storing toner for each of said separate
color separation images in separate reservoirs; and applying toner
from each of said separate toner reservoirs onto each of said
corresponding plurality of display screens.
26. A method according to claim 25 wherein said step of erasing
said displayed image comprises the steps of: removing said toner
from each of said plurality of display screens; and storing said
removed toner for reuse in said separate toner reservoirs.
Description
[0001] This is a Continuation of U.S. patent application Ser. No.
09/781,900 currently pending
FIELD OF THE INVENTION
[0002] The present relates to display boards in general and to
remotely changing the displayed information on the display boards
in particular.
BACKGROUND OF THE INVENTION
[0003] One common form of display utilizes poster displays usually
located at strategic road junctions for maximum effect. Such
posters are commonly pasted on large display boards and remain for
the time period paid for, after which the poster is replaced. A
major disadvantage of the poster display is that it is restricted
to displaying one poster at a time.
[0004] In order to maximize the available net display area, various
systems have been developed which allow several, usually not more
than three, separate advertisements to be displayed on the same
display area. One system uses a rotating screen which contains two
advertisements, one of which is visibly displayed at a time.
[0005] A second system utilizes a plurality of rotatable triangular
slats which allows three separate advertisements to be shown. Each
advertisement occupies the whole display area and is cut into
strips to enable the slats to be rotated. The slats can be rotated
at regular intervals so that each of the three advertisements is
consequently displayed.
[0006] These existing systems are also limited in that in order to
change the one or more of the advertisements, it is necessary to
physically replace the poster in situ.
[0007] One of the methods for forming an image on a surface is
electrophotography. Electrophotography forms a latent image on a
photoconductor which is then developed using toner. The toner image
is then transferred to a substrate.
[0008] Another technique for non-contact printing and imaging is
ionography. An example of ionography, by the transfer of
electrostatic images on to a dielectric surface using toner, is
described in U.S. Pat. No. 5,289,214 to Zur.
[0009] Computer controlled display systems are usually based on
some kind of projection of an image. The practical solutions, due
to the limited power of the lamp are such that the image cannot be
seen with a good contrast in outdoor applications, due to the high
brightness of the ambient sunlight.
[0010] This invention works in reflection mode like the classical
poster display, that is it uses the ambient light as light
source.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a display
system that can be remotely changed, so that different images are
successively displayed with minimal interruption.
[0012] A further object of the present invention is to utilize
ionography techniques for non-contact printing and imaging for
display. Thus by exploiting electrostatic imaging techniques, an
advertisement can be displayed promptly by transferring a toner
image onto an imaging belt.
[0013] A further object of the present invention is to provide a
display board that can be used both during daylight and at
night.
[0014] There is thus provided, in accordance with a preferred
embodiment of the present invention, a display system which
includes at least one display screen, printing means for
transferring color images on to the at least one display screen,
erasing means for erasing the color images from the at least one
display screen and drive means connected to the at least one
display screen for operatingly moving the at least one display
screen.
[0015] Furthermore, in accordance with a preferred embodiment of
the present invention, the drive means moves the at least one
display screen from a first printing position to a second viewing
position.
[0016] In addition, in accordance with a preferred embodiment of
the present invention, the system according to claim 1 further
includes an interface control unit coupled to at least the at least
one display screen and processing means communicating with the
interface control unit to control the display of the images.
[0017] Furthermore, in accordance with a preferred embodiment of
the present invention, the display screen includes a plurality of
display screens, each of which displays a separate color separation
of the image.
[0018] In addition, in accordance with a preferred embodiment of
the present invention, the system also includes a dual purpose
screen having a substantially white reflective diffusing portion
and a substantially transparent portion and a substantially
transparent protective screen placed in front of the at least one
display screen. Each of the plurality of display screens includes
an endless dielectric imaging belt.
[0019] Furthermore, in accordance with a preferred embodiment of
the present invention, each of the separate color separation images
is a digitized version for one of each of the three color
separations of cyan, magenta and yellow (C, M and Y).
[0020] In addition, in accordance with a preferred embodiment of
the present invention, the printing means includes a separate toner
reservoir for each of the separate color separation images and
writing means for applying toner from each of the separate toner
reservoirs onto each of the at least one display screen.
[0021] Furthermore, in accordance with a preferred embodiment of
the present invention, the erasing means includes static
eliminators for cleaning and erasing the toner from the at least
one display screen and at least one receptacle for the at least one
display screen for receiving and storing the removed toner. The
static eliminators comprise one of a group of eliminators including
active hot static eliminators; active shockless static eliminators
and passive static eliminators.
[0022] Furthermore, in accordance with a preferred embodiment of
the present invention, the system further includes pumping means to
transfer toner from each of the at least one-receptacles to the
corresponding toner reservoir.
[0023] In addition, in accordance with a preferred embodiment of
the present invention, the drive means is connected to the dual
purpose screen for operatingly moving the dual purpose screen from
a first position wherein the substantially white reflective
diffusing portion is placed behind the at least one display screen
to a second position wherein the substantially transparent portion
is placed behind the at least one display screen.
[0024] Additionally, there is provided a display system which
includes a single display screen and a plurality of printing
arrangements located adjacent it, each printing arrangement for
each of base colors.
[0025] Furthermore, in accordance with a preferred embodiment of
the present invention, the interface control unit is coupled to the
drive means.
[0026] The system further includes a roller track for supporting
the writing means thereby to allow the writing means to be moved
longitudinally along the track. The roller track further supports
the erasing means thereby to allow the erasing means to be moved
longitudinally along the track.
[0027] Furthermore, in accordance with a preferred embodiment of
the present invention, the movement of the printing means and
erasing means is controlled by the interface and control unit.
[0028] Additionally, there is provided, in accordance with a
preferred embodiment of the present invention, a method for
producing at least one display image onto a screen. The method
includes the steps of:
[0029] preparing the at least one display image;
[0030] communicating the at least one display image to an interface
and control unit;
[0031] printing the prepared at least one display image on to at
least one display screen; and
[0032] moving the at least one display screen into position for
viewing.
[0033] Furthermore, in accordance with a preferred embodiment of
the present invention, the method further includes the step of
erasing the displayed image and also includes the steps of:
[0034] preparing a replacement display image; and
[0035] communicating the replacement display image to the interface
and control unit.
[0036] In addition, in accordance with a preferred embodiment of
the present invention, the method further includes the step of
concurrently printing the replacement display image while the first
displayed image is being erased, the step of printing the
replacement display image on a separate part of the at least one
display screen while the first image is being displayed and the
step of erasing an image and concurrently printing a replacement
display image on a separate part of the at least one display screen
while another image is being displayed.
[0037] Alternatively, the method may comprise the step of
depositing base colors images to a single display screen
concurrently.
[0038] Furthermore, in accordance with a preferred embodiment of
the present invention, the method further includes the step of
moving a dual purpose screen having a substantially white
reflective diffusing portion and a substantially transparent
portion behind the at least one display screen. Moving includes the
step of activating the dual purpose screen to move the
substantially transparent portion behind the at least one display
screen whenever the amount of light falls below a pre-determined
level.
[0039] In addition, in accordance with a preferred embodiment of
the present invention, the printing step includes the steps of:
[0040] storing toner for each of the separate color separation
images in separate reservoirs; and
[0041] applying toner from each of the separate toner reservoirs
onto each of the corresponding plurality of display screens.
[0042] Finally, the step of erasing the displayed image includes
the steps of removing the toner frond each of the plurality of
display screens and storing the removed toner for reuse in the
separate toner reservoirs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The present invention will be understood and appreciated
more fully from the following detailed description taken in
conjunction with the appended drawings in which:
[0044] FIG. 1 is a schematic illustration of a display system,
according to a preferred embodiment of the present invention.
[0045] FIG. 2 is a high level block diagram illustration of the
components of the display system of FIG. 1;
[0046] FIG. 2A is a high level block diagram illustration of the
components of the display system of FIG. 1 when a single display
screen is used.
[0047] FIG. 3 is a side elevational view of the display screen of
FIG. 1;
[0048] FIG. 3A is a side elevational view of the display screen of
FIG. 1 when a single display screen is used.
[0049] FIG. 4 is a detailed schematic isometric view of one of the
display screens of FIG. 1;
[0050] FIG. 5 is a high level block diagram illustration of the
operation of preparing an advertisement for display.
[0051] FIG. 6 is a high level block diagram illustration of the
operational steps for producing a display advertisement;
[0052] FIG. 7A is a flow chart illustration of the operational
steps of a preferred embodiment for producing an interchangeable
display; and
[0053] FIG. 7B is a flow chart illustration of the operational
steps of a further preferred embodiment for producing an
interchangeable display.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0054] Reference is now made to FIGS. 1-3A. FIG. 1 is a schematic
illustration of a display system, generally designated 10,
according to a preferred embodiment of the present invention. FIGS.
2 and 2A are high level block diagram illustrations of the
components of the display system 10. FIGS. 3 and 3A are side view
of the display screen 12, used in the system.
[0055] The display system 10 comprises a display screen, generally
designated 12 connected, via an interface and control unit 14, to a
computer system 16. Computer system 16, which is preferably
situated at a separate central location, remotely communicates with
interface and control unit 14 to direct the operation and control
the display of an image 15 on the display screen 12. The display
system 10 further comprises drive means 18, operable by computer
system 16 via interface and control unit 14, printing means,
generally designated 20, for depositing color images on to the
display screen 12, and erasing means, generally designated 22, for
erasing or removing the deposited toner. Printing means 20 and
erasing means 22 are connected to interface and control unit
14.
[0056] Display screen 12 comprises a plurality of display screens
26, 28 and 30, which are superimposed on each other, each of which
is utilized to display a different color. The plurality of display
screens 26, 28 and 30 are situated one behind the other so that the
display screen 12 displays a composite image comprising the three
images deposited on each of the display screens 26, 28 and 30.
[0057] A plurality of printing means 20, one for each of display
screens 26, 28 and 30 is placed proximate to the screens, to
deposit color images on the display screens to create the complete
advertisement. The erasing means 22 are used to remove or erase the
deposited toner. Printing means 20 and erasing means 22 are located
adjacent to each of the three display screens 26, 28 and 30.
[0058] Display screen 12 comprises a dual purpose screen 24 and
three display screens, referenced 26, 28 and 30 which are located
close to one another and in front of the dual purpose screen 24.
Each of the three display screens 26, 28 and 30 are similar.
[0059] Alternatively, as shown in FIG. 3A, the display screen
comprise a single display screen 29 on which a color image is
created by employing a plurality of printing means 20C, 20M, 20Y
and 20K, one for each color, situated located adjacent display
screen 29.
[0060] Preferably, a transparent screen 35 is also placed in front
of the display screens 26, 28 and 30 or in front of screen 29 in
order to protect the screens from the elements.
[0061] Dual purpose screen 24 comprises a continuous loop of
material stretched over a plurality of rollers 32. In the example
of the embodiment of FIGS. 3 and 4, dual purpose screen 24
comprises two different types of screen, a white screen 34 which is
substantially opaque for use during daylight and a transparent
screen 36 for use during the hours of darkness. The dual purpose
screen 24 may be rotated in either clockwise or anti-clockwise
direction to select the required screen, as appropriate, that is,
white screen 34 for daylight use or transparent screen 36 for night
use.
[0062] A backlighting system, generally designated 38 for use with
the transparent screen 36 during night use is connected to
interface and control unit 14.
[0063] Reference is now also made to FIG. 4 which is a detailed
schematic isometric view of one of the display screens (26, 28 or
30). Each of the three display screens 26, 28 and 30 comprises an
endless loop (or belt), generally designated 40, of image
separation sheet material on to which a specific color toner image
is transferred. Preferably, the loop of material for each of three
display screens 26, 28 and 30 is composed of a dielectric imaging
belt 40, composed of polyester, for example. For the purposes of
example only, loop 40 is shown as having a triangular configuration
consisting of a base 52, a front display side 54 and a hypotenuse
56.
[0064] In the embodiment of a single display screen 29 a single
endless loop (or belt), is used.
[0065] Printing means 20 and erasing means 22 are suitably
supported, for example by a pair of stands 58, each having a roller
track 60 affixed thereto. Both printing means 20 and erasing means
22 are movable longitudinally along the tracks 60, as illustrated
by arrows 62 and 64, respectively. The movement of printing means
20 and erasing means 22 is controlled by interface and control unit
14.
[0066] In another embodiment of a single display screen, plurality
of printing means 20C, 20M, 20Y and 20K, and erasing means 22 are
suitably supported, for example by a pair of stands 58, each having
a roller track 60 affixed thereto. Both printing means 20 and
erasing means 22 are movable longitudinally along the tracks 60, as
illustrated by arrows 62 and 64, respectively. The movement of
printing means 20 and erasing means 22 is controlled by interface
and control unit 14. Alternatively, printing means 20 and erasing
means 22 may be stationary, while the needed relative movement
between these means and the display screen may be achieved by way
of movement of the display screen.
[0067] The display system 10 produces color images by depositing
three separate images onto each of the three display screens 26, 28
and 30. Each separate image is a digitized version (or separation
file), one for each of the three color separations of cyan, magenta
and yellow (C, M and Y).
[0068] According to another embodiment of the invention of a single
screen, display system 10 produces color images by combining images
deposited for each base color, using a plurality of printing means
20, one for each of base color. Erasing of the images is carried
out by using erasing means 22.
[0069] Drive means 18 may comprise any suitable apparatus for
moving the display screens 26, :28 and 30 and the dual purpose
screen 24, such as electrically or hydraulically operated motors,
for example.
[0070] Reference is now made to FIG. 5, which is a block diagram
illustration of the operation of preparing an advertisement for
display.
[0071] Printing means 20, which is located adjacent to each belt 40
of the three display screens 26, 28 and 30, is similar for each of
the three display screens 26, 28 and 30. Printing means 20
comprises a toner reservoir, generally referenced 42, and writing
means, generally designated 44, for each of the four color
separations of cyan, magenta yellow and black.
[0072] For reference, the various components (reservoirs, writing
means) for each of the three color separations of cyan, magenta
yellow and black are identified by a suffix (C, M Y or K)
indicating their color (Cyan, Magenta or Yellow). Thus reservoir
42M and writing means 44M refer to screen 28 which receives the
magenta color. Alternatively a single screen may be used.
[0073] The image is transferred by means of an ionographic writing
head, such as manufactured by Delphax Systems of Canton, Mass.,
United States. Briefly, the print system consists of a multi-stage
process for transferring the image onto imaging belt 40 and
optionally erasing the imaged message.
[0074] Firstly, using ion-deposition, a latent charge image is
formed on imaging belt 40. Then the image is developed by applying
toner of the respective color (C, M Y or K), contained in the
corresponding reservoir 42C, 42M 42Y or 42K. Preferably, the toner
has transmission characteristics similar to those in standard
xerographic reproduction equipment.
[0075] Each of the image separation sheets (of display screens 26,
28 and 30) are similarly prepared, that is toner of the respective
color is applied to each sheet.
[0076] The sheets are then moved into position, one behind the
other, behind transparent screen 35 so that the combination of
display screens 26, 28 and 30 form the complete image for
viewing.
[0077] According to another embodiment of the invention only single
display screen 29 is employed along each four printing means 20M,
20C 20Y and K, that are situated adjacently. Using ion-deposition,
a latent charge image is formed on imaging belt 40. Then the image
is developed by applying toner of the respective color (C, M, Y or
K), contained in the corresponding reservoir 42C, 42M, 42Y or K.
Preferably, the toner has transmission characteristics similar to
those in standard xerographic reproduction equipment.
[0078] During daylight hours, the white screen 34 portion of dual
purpose screen 24 is moved into position. Whenever the amount of
light falls below a pre-determined level, such as during the night,
the dual purpose screen 24 is activated to move so that the
transparent screen 36 portion of the dual purpose screen 24 is
placed behind the display screens 26, 28 and 30, and the back
lighting system 38 is operated.
[0079] To remove or erase the image from each of the image
separation sheets (of display screens 26, 28 and 30), the relevant
imaging belt 40 is rotated clockwise so as to come into contact
with erasing means 22. Erasing means 22 comprise static
eliminators, generally designated 46, for cleaning and erasing the
toner of a previous image from the display screens 26, 28 and 30
and at least one receptacle, generally referenced 48, for receiving
and storing the respective toner being removed. A new image can now
be applied by writing units 44, and then moved into position for
displaying. In another embodiment of the invention to remove or
erase the image from the image screen, the imaging belt 40 is
rotated clockwise so as to come into contact with erasing means
22.
[0080] A pump 50, or other transfer means, connects each storage
receptacle 48 to the corresponding reservoir 42. Removed toner can
then be reused for the next display.
[0081] The static eliminators 46, are commercially available active
or passive eliminators, such as those manufactured by Chapman Inc.
of Portland, Me., USA.
[0082] Basically, active static eliminators which may be "hot" or
shockless, combine emitter points to create ions and a high voltage
power supply to control the electrical energy delivered to the
emitters. Sufficiently high energy is used to induce Ionization
without causing arcing. Hot bars which produce more ionization, are
used where they can be mounted out of the way of human contact. The
emitter points of shockless static eliminators receive their high
voltage indirectly via a resistor or capacitor so that the a low
level current is passed.
[0083] Passive static eliminators basically work by induction
similar to a lightning rod and generally comprise tinsel or
brushes.
[0084] Reference is now made to FIG. 6 which is high level block
diagram illustration of the operational steps for producing a
display, such as an advertisement.
[0085] The advertisement to be displayed is first prepared on the
computer system 16, using a graphic arts program or similar (step
202). The computer system 16, transfers details of the
advertisement and other display commands by radio or other remote
transfer means to the interface and control unit 14 (step 204).
[0086] The interface and control unit 14, which is connected to the
display screen 12, relays the commands received from the computer
system 16 to the various operational devices (step 240).
[0087] Basically, there are three kinds of operational commands
(step 240) which may be transmitted, as follows:
[0088] a) for the operation of the drive means 18 (step 242);
[0089] b) instructions for writing, that is depositing toner on any
or all of the screens (step 244); and
[0090] c) instructions for removing toner (step 246).
[0091] The operation of the drive means 18 (step 242) may move any
or all of the display screens 26, 28 and 30 (step 248), change the
dual purpose screen 24 (step 250) and switch the backlighting
system 38 (step 252) on/off.
[0092] There are several alternative combinations of step sequences
which may be performed for writing, displaying or erasing the
advertisement. For example, toner can be deposited according to the
image (step 244), and as described in the embodiment of FIG. 3,
simultaneously moved into position (step 248). Also, each screen
can be prepared either concurrently or consecutively.
Alternatively, as described hereinbelow, the image can be first
deposited and later, when the image has been completed, moved into
viewing position.
[0093] The steps of changing the dual purpose screen 24 (step 252)
and switching the backlighting system 38 (step 254) on/off are
carried out as necessary depending on the prevailing lighting
conditions.
[0094] Reference is now made to FIGS. 7A and 7B, which are flow
chart illustrations of the operational steps of embodiments for
producing interchangeable display. Operational steps which are
similar to operational steps which have been previously described
with respect to the preferred embodiment hereinabove, are similarly
designated and will not be further described.
[0095] Referring to a first embodiment to produce an
interchangeable advertisement display (FIG. 7A), each of the three
display screens 26, 28 and 30, is configured for at least two
advertisements, using the same writing means 44 for writing both
images to be displayed.
[0096] In this embodiment, the first advertisement is prepared on
the computer system 16, using a graphic arts program or similar
(step 202). The computer system 16, transfers commands by radio or
other remote transfer means to the interface and control unit 14
(step 204).
[0097] The interface and control unit 14, which is connected to the
display screen 12, relays the commands received from the host
computer 16 for depositing toner on the three display screens 26,
28 and 30 (step 210) from the writing means 44 and simultaneously
the three screens are moved into position (step 208).
[0098] To display a replacement advertisement, the replacement
advertisement is prepared and transferred to the interface and
control unit 14 (steps 210 and 212), similar to steps 202 and 204
described for the first advertisement. The first advertisement is
erased (step 214) and the second different advertisement is written
onto the screen (step 206) and displayed on display screens 26, 28
and 30 (step 208). Erasure of the first advertisement takes place
at the same time as the screen is being moved, and the next
advertisement is being written onto the screen. Further
advertisements can be prepared and displayed by repeating the steps
206-214 (dashed box 220).
[0099] As will be appreciated, while the first advert is being
written to a clean screen, erasure does not take place.
[0100] In an alternative embodiment, illustrated in FIG. 7B, after
the first advertisement has been prepared (step 202) and is being
displayed (step 204), a second advertisement is prepared and
transferred to the interface and control unit 14 (steps 210 and
212), The second advertisement can be written to an available blank
part of the display screens 26, 28 and 30, which is out of view of
the dual purpose screen 24, at the same time as the first
advertisement is being displayed (step 222).
[0101] In this embodiment printing means 20 are moved
longitudinally along the tracks 60 (FIG. 3), so as to cover the
whole surface of the screen, without moving the screen (step 222).
Similarly, erasing means 22 can also be moved longitudinally along
the tracks 60 to erase the image (step 226) without the necessity
for moving the screen.
[0102] In yet another embodiment the printing means and the erasing
means may be stationary, while the printing and erasing operations
are performed when the display screen is moved to its next
position.
[0103] To display the second advertisement, display screens 26, 28
and 30 are rotated so that the second advertisement is brought in
front of the dual purpose screen 24 and the first advertisement is
hidden from view (step 224). Steps 210-226 (dashed box 230) can be
repeated for other replacement advertisements.
[0104] It will be appreciated by persons knowledgeable in the art
that the present invention is not limited to the printing methods
described hereinabove but is also applicable to other methods such
as ink-jet printing. Furthermore, the present invention is not
limited to being controlled by a remote host but that a stand alone
system in which a plurality of alternating print advertisements are
stored in a buffer may also be used.
[0105] It will be appreciated by persons skilled in the art that
the present invention is not limited by what has been particularly
shown and described herein above. Rather the scope of the invention
is defined by the claims which follow:
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